scholarly journals A method for selective intracellular labeling of immunostained neurons in turtle retina.

1993 ◽  
Vol 41 (4) ◽  
pp. 635-641 ◽  
Author(s):  
E Fernandez ◽  
H Kolb
Keyword(s):  
Substance P ◽  
Ganglion Cells ◽  
Lucifer Yellow ◽  
Dendritic Tree ◽  
Visual Control ◽  
Field Size ◽  
Large Field ◽  
Intracellular Staining ◽  
Good Penetration ◽  
Triton X

We describe a method for direct intracellular staining under visual control of immunolabeled neurons in the turtle retina. Substance P was the antiserum used. It labels two different sizes of ganglion cells in turtle retina. Intracellular labeling under visual control was achieved by iontophoresis of Lucifer yellow or Neurobiotin. The best immunolabeling of substance P-immunoreactive (SP-IR) ganglion cells occurred after either Triton X-100 or freeze-thaw techniques to get good penetration of the antisera. However, this inevitably resulted in leaky cells and inadequate morphology of the ganglion cells subsequently stained by Lucifer yellow and Neurobiotin. Most successful immunocytochemical labeling followed by intracellular labeling was achieved with light fixation (15 min in 4% paraformaldehyde) and long incubation time in the primary antiserum (4 days). Before intracellular labeling, dendritic tree shape, dendritic field size, and stratification of SP-IR ganglion cells were not sufficiently revealed for correct classification of these cells. After the selective intracellular staining described here, we were able to identify and characterize one of the populations of substance P-IR ganglion cells types as large-field, monostratified G20 ganglion cells.

Morphology, dendritic field size, somal size, density, and coverage of M and P retinal ganglion cells of dichromatic Cebus monkeys

1996 ◽  
Vol 13 (6) ◽  
pp. 1011-1029 ◽  
Author(s):  
Elizabeth S. Yamada ◽  
Luiz Carlos L. Silveira ◽  
V. Hugh Perry
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Dendritic Tree ◽  
Field Size ◽  
Retinal Eccentricity ◽  
Temporal Region ◽  
Retinal Ganglion ◽  
Dendritic Field ◽  
Retrograde Filling

AbstractMale Cebus monkeys are all dichromats, but about two thirds of the females are trichromats. M and P retinal ganglion cells were studied in the male Cebus monkey to investigate the relationship of their morphology to retinal eccentricity. Retinal ganglion cells were retrogradely labeled after optic nerve deposits of biocytin to reveal their entire dendritic tree. Cebus M and P ganglion cell morphology revealed by biocytin retrograde filling is similar to that described for macaque and human M and P ganglion cells obtained by in vitro intracellular injection of HRP and neurobiotin. We measured 264 and 441 M and P ganglion cells, respectively. M ganglion cells have larger dendritic field and cell body size than P ganglion cells at any comparable temporal or nasal eccentricity. Dendritic trees of both M and P ganglion cells are smaller in the nasal than in the temporal region at eccentricities greater than 5 mm and 2 mm for M and P ganglion cells, respectively. The depth of terminal dendrites allows identification of both inner and outer subclasses of M and P ganglion cells. The difference in dendritic tree size between inner and outer cells is small or absent. Comparison between Cebus and Macaca shows that M and P ganglion cells have similar sizes in the central retinal region. The results support the view that M and P pathways are similarly organized in diurnal dichromat and trichromat primates.

Computer simulations of voltage clamping retinal ganglion cells through whole-cell electrodes in the soma

1996 ◽  
Vol 75 (5) ◽  
pp. 2129-2143 ◽  
Author(s):  
T. J. Velte ◽  
R. F. Miller
Keyword(s):  
Voltage Clamp ◽  
Retinal Ganglion Cells ◽  
Computer Simulations ◽  
Ganglion Cells ◽  
Dendritic Tree ◽  
Large Field ◽  
Retinal Ganglion ◽  
Whole Cell ◽  
Voltage Clamping ◽  
Whole Cell Recordings

1. Computer simulations of voltage-clamp experiments in retinal ganglion cells were implemented to better understand the insights that can be obtained with this physiological approach. 2. Simulation studies of voltage clamping were based on the contemporary approach of using whole-cell recordings with low resistance electrodes attached to the soma. Realistic ganglion cell morphologies were provided by cell staining experiments in the mudpuppy retina; selected cells included small-, medium-, and large-field neurons whose morphologies were entered into a computer through a neuron tracing program. 3. Values for the specific membrane resistance (Rm) varied from 5,000 to 100,000 omega/cm2 to conform to the range of Rm values obtained with intracellular sharp electrodes and whole-cell recordings. 4. Synaptic input currents were simulated by injecting current with and without an underlying conductance change into different regions of the dendritic tree. The time-variant waveform of the current included a combined transient and sustained component similar to the waveform of ON-bipolar activation. 5. Simulations were base on 1) intact structures, which included the soma and the entire dendritic tree, and 2) a more limited cell geometry that included representation of the soma, but only part of the dendritic tree, to represent the restricted morphology that might be rendered after cutting the retina into 150-microns cross sections for retinal slice experiments. 6. The results of this study indicate that voltage clamping from the soma, with optimal, low resistance electrodes and series resistance compensation, provides an error-free voltage clamp for slow signals that are generated within a small electrotonic distance from the soma (approximately 0.1 lambda). 7. The ideal voltage-clamp conditions are optimized when synaptic conductances are small and nonlinear membrane elements are minimally activated: small-field neurons best approximate these conditions, but clamping errors are evident in these cells when more distal branches are activated. The degree of error in voltage clamping was much greater when medium-and large-field neurons were evaluated. 8. It was not possible to clamp action potentials (nonpropagating) even when they were generated near the soma in any of the three model cells examined. 9. Experimental paradigms were developed to demonstrate that inadequate voltage clamping can lead to errors in the interpretation of experimental data when relevant variables are not taken into consideration. Suggestions are made for determining and optimizing favorable clamp conditions.

Quantitative morphology of rabbit retinal ganglion cells

1983 ◽  
Vol 217 (1208) ◽  
pp. 341-355 ◽  
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Dendritic Tree ◽  
Dendritic Morphology ◽  
Field Size ◽  
Retinal Eccentricity ◽  
Inner Plexiform Layer ◽  
Retinal Ganglion ◽  
Dendritic Fields

Intraretinal (extracellular) injections of horseradish peroxidase were used to stain rabbit retinal ganglion cells. Five basic morphological ganglion cell classes were identified by quantitative analysis of dendritic branching patterns and computer reconstruction of dendritic ramification levels. Type 1 cells are characterized by a unistratified, radial dendritic morphology. The dendritic fields are of medium to large size. Subgroups ramify in either the outer or the inner part of the inner plexiform layer (i. p. l.). Type 2 cells have complex intricately branched dendritic morphologies with wide branch angles. They are comparable with type 1 cells in dendritic field size. Subgroups of this class include unistratified cells ramifying in the outer or inner part of the i. p. l. as well as cells with more complicated i. p. l. ramification schemes. Type 3 cells are somewhate similar to type 1 cells. A particular distinction is that they are much larger than type 1 cells at the same retinal eccentricity. Type 4 cells have a thin elliptical soma and a lobulate dendritic tree structure. Type 5 cells are a somewhat heterogeneous group with very small intricately branched dendritic fields. Since the number of anatomical groups is comparable with the number of physiological classes, it is tenable that the major physiological cell classes are associated with distinct dendritic morphologies.

scholarly journals A novel system for the classification of diseased retinal ganglion cells

2014 ◽  
Vol 31 (6) ◽  
pp. 373-380 ◽  
Author(s):  
JAMES R. TRIBBLE ◽  
STEPHEN D. CROSS ◽  
PAULINA A. SAMSEL ◽  
FRANK SENGPIEL ◽  
JAMES E. MORGAN
Keyword(s):  
Ganglion Cells ◽  
Primary Dendrite ◽  
Dendritic Tree ◽  
Principal Component ◽  
Classification Model ◽  
Field Size ◽  
Brown Norway ◽  
The Sun ◽  
Retinal Ganglion

AbstractRetinal ganglion cell (RGC) dendritic atrophy is an early feature of many forms of retinal degeneration, providing a challenge to RGC classification. The characterization of these changes is complicated by the possibility that selective labeling of any particular class can confound the estimation of dendritic remodeling. To address this issue we have developed a novel, robust, and quantitative RGC classification based on proximal dendritic features which are resistant to early degeneration. RGCs were labeled through the ballistic delivery of DiO and DiI coated tungsten particles to whole retinal explants of 20 adult Brown Norway rats. RGCs were grouped according to the Sun classification system. A comprehensive set of primary and secondary dendrite features were quantified and a new classification model derived using principal component (PCA) and discriminant analyses, to estimate the likelihood that a cell belonged to any given class. One-hundred and thirty one imaged RGCs were analyzed; according to the Sun classification, 24% (n = 31) were RGCA, 29% (n = 38) RGCB, 32% (n = 42) RGCC, and 15% (n = 20) RGCD. PCA gave a 3 component solution, separating RGCs based on descriptors of soma size and primary dendrite thickness, proximal dendritic field size and dendritic tree asymmetry. The new variables correctly classified 73.3% (n = 74) of RGCs from a training sample and 63.3% (n = 19) from a hold out sample indicating an effective model. Soma and proximal dendritic tree morphological features provide a useful surrogate measurement for the classification of RGCs in disease. While a definitive classification is not possible in every case, the technique provides a useful safeguard against sample bias where the normal criteria for cell classification may not be reliable.

Dendritic integration in ganglion cells of the mudpuppy retina

1995 ◽  
Vol 12 (1) ◽  
pp. 165-175 ◽  
Author(s):  
T.J. Velte ◽  
R.F. Miller
Keyword(s):  
Functional Organization ◽  
Simulation Analysis ◽  
Ganglion Cells ◽  
Impedance Matching ◽  
Dendritic Tree ◽  
Membrane Resistance ◽  
Transient Responses ◽  
Dendritic Integration ◽  
Necturus Maculosus ◽  
Integration Efficiency

AbstractComputer simulations were carried out to evaluate the influence of varying the membrane resistance (Rm) on the dendritic integration capacity of three classes of ganglion cells in the mudpuppy (Necturus maculosus) retina. Three broadly different morphological classes of ganglion cells were selected for this study and represent the range of dendritic tree sizes found in the ganglion cell population of this species. Simulations were conducted on anatomical data obtained from cells stained with horseradish peroxidase; each cell was traced, using a computer as an entry device and later converted to a compartmental (electrical) representation of the cell. Computer-simulation analysis used a time-variant conductance change which was similar in waveform to light-activated bipolar cell input. The simulated membrane resistance for each cell varied between 5000 and 100,000 Ω cm2, and conductance changes were introduced into different regions of the soma-dendritic tree to evaluate dendritic integration efficiency. When higher values of Rm are used, even the largest cells become electrotonically compact and attenuation of voltage responses is minimized from distal to soma regions. Responses were less attenuated from proximal to distal regions of the cell because of the favorable impedance matching, and because less current is required to polarize small “sealed” dendritic terminations. Steady-state responses integrate more effectively than transient responses, particularly when Rm is high, since transient responses were more attenuated by the membrane capacitance. The possibility that Rm is a dynamic property of retinal ganglion cells is discussed in view of the functional organization of dendritic integration efficiency as Rm fluctuates from low to high values.

A coupled network for parasol but not midget ganglion cells in the primate retina

1992 ◽  
Vol 9 (3-4) ◽  
pp. 279-290 ◽  
Author(s):  
Dennis M. Dacey ◽  
Sarah Brace
Keyword(s):  
Nearest Neighbor ◽  
Ganglion Cells ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Cell Types ◽  
Distinct Pattern ◽  
Field Size ◽  
Inner Plexiform Layer ◽  
Dendritic Field

AbstractIntracellular injections of Neurobiotin were used to determine whether the major ganglion cell classes of the macaque monkey retina, the magnocellular-projecting parasol, and the parvocellular-projecting midget cells showed evidence of cellular coupling similar to that recently described for cat retinal ganglion cells. Ganglion cells were labeled with the fluorescent dye acridine orange in an in vitro, isolated retina preparation and were selectively targeted for intracellular injection under direct microscopic control. The macaque midget cells, like the beta cells of the cat's retina, showed no evidence of tracer coupling when injected with Neurobiotin. By contrast, Neurobiotin-filled parasol cells, like cat alpha cells, showed a distinct pattern of tracer coupling to each other (homotypic coupling) and to amacrine cells (heterotypic coupling).In instances of homotypic coupling, the injected parasol cell was surrounded by a regular array of 3–6 neighboring parasol cells. The somata and proximal dendrites of these tracer-coupled cells were lightly labeled and appeared to costratify with the injected cell. Analysis of the nearest-neighbor distances for the parasol cell clusters showed that dendritic-field overlap remained constant as dendritic-field size increased from 100–400 μm in diameter.At least two amacrine cell types showed tracer coupling to parasol cells. One amacrine type had a small soma and thin, sparsely branching dendrites that extended for 1–2 mm in the inner plexiform layer. A second amacrine type had a relatively large soma, thick main dendrites, and distinct, axon-like processes that extended for at least 2–3 mm in the inner plexiform layer. The main dendrites of the large amacrine cells were closely apposed to the dendrites of parasol cells and may be the site of Neurobiotin transfer between the two cell types. We suggest that the tracer coupling between neighboring parasol cells takes place indirectly via the dendrites of the large amacrine cells and provides a mechanism, absent in midget cells, for increasing parasol cell receptive-field size and luminance contrast sensitivity.

scholarly journals Immunohistochemical evidence for the presence of a vasoactive intestinal peptide, neuropeptide Y and substance P in rat adrenal medulla after heat stress

2012 ◽  
Vol 64 (1) ◽  
pp. 7-13
Author(s):  
Dragana Petrovic-Kosanovic ◽  
Vesna Koko
Keyword(s):  
Heat Stress ◽  
Substance P ◽  
Neuropeptide Y ◽  
Vasoactive Intestinal Peptide ◽  
Adrenal Medulla ◽  
Chromaffin Cells ◽  
Ganglion Cells ◽  
Nerve Fibers ◽  
Acute Heat Stress ◽  
Immunohistochemical Evidence

Immunohistochemistry revealed the presence of VIP-, NPY- and SP-immunoreactivity in the rat adrenal medulla. VIP- and NPY-immunoreactivity was detected in chromaffin and ganglion cells and in nerve fibers, but SP-immunoreactivity was found only in chromaffin cells. After acute heat stress, VIP- and NPY- immunoreactivities in cells and nerve fibers were reduced, probably as a result of the release of these peptides with catecholamines. The absence of SP-immunoreactive ganglion cells in the adrenal medulla suggests that the SP-immunoreactive nerve fibers are extrinsic in origin.

The morphology and topographic distribution of AII amacrine cells in the cat retina

1985 ◽  
Vol 224 (1237) ◽  
pp. 475-488 ◽  
Keyword(s):  
Ganglion Cells ◽  
Lucifer Yellow ◽  
Central Area ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Dendritic Morphology ◽  
Inner Plexiform Layer ◽  
Cat Retina ◽  
Superior Margin ◽  
Aii Amacrine Cells

When cat retina is incubated in vitro with the fluorescent dye, 4',6- diamidino-2-phenyl-indole (DAPI), a uniform population of neurons is brightly labelled at the inner border of the inner nuclear layer. The dendritic morphology of the DAPI-labelled cells was defined by iontophoretic injection of Lucifer yellow under direct microscopic control: all the filled cells had the narrow-field bistratified morphology that is distinctive of the A ll amacrine cells previously described from Golgistained retinae. Although the A ll amacrines are principal interneurons in the rod-signal pathway, their density distribution does not follow the topography of the rod receptors, but peaks in the central area like the cone receptors and the ganglion cells. There are some 512000 A ll amacrines in the cat retina and their density ranges from 500 cells per square millimetre at the superior margin to 5300 cells per square millimetre in the centre (retinal area is 450 mm2). The isodensity contours are kite-shaped, particularly at intermediate densities, with a horizontal elongation towards nasal retina. The cell body size and the dendritic dimensions of A ll amacrines increase with decreasing cell density. The lobular dendrites in sublamina a of the inner plexiform layer span a restricted field of 16—45 pm diameter, while the arboreal dendrites in sublamina b form a varicose tree of 18—95 pm diameter. The dendritic field coverage of the lobular appendages is close to 1.0 (+ 0.2) at all eccentricities whereas the coverage of the arboreal dendrites doubles within the first 1.5 mm and then remains constant at 3.8 ( + 0.7) throughout the periphery.

scholarly journals Commissioning Measurements of Electron Beam Using Montecarlo Algorithm on Truebeam STx® and Compariaon with Clinac iX Linear Accelerator

2021 ◽  
Vol 229 ◽  
pp. 01041
Author(s):  
Kamal Saidi ◽  
Redouane El Baydaoui ◽  
Hanae El Gouach ◽  
Othmane Kaanouch ◽  
Mohamed Reda Mesradi
Keyword(s):  
Electron Beam ◽  
Electron Beams ◽  
Measured Data ◽  
University Hospital ◽  
Field Size ◽  
Large Field ◽  
Water Phantom ◽  
Depth Dose ◽  
International University ◽  
The Absolute

TrueBeam STx latest generation linear accelerators (linacs) installed at Sheikh Khalifa International University Hospital in Casablanca, Morocco. The aim of this is to present and compare the result of the Electron commissioning measurement on TrueBeam Stx and clinac iX installed at Sheikh Khalifa International University Hospital in Casablanca, Morocco. A compariaon of eMC calculations and measurements for TrueBeam Stx were evaluated. Dosimetric parameters are systematically measured using a large water phantom 3D scanning system MP3 Water Phantom (PTW, Freiburg, Germany). The data of the electron beams commissioning including depth dose curves for each applicator, depth dose curves without applicator and the profile in air for a large field size 40x 40cm2, and the Absolute Dose (cGy/MU) for each applicator. All the data were examined and compared for five electron beams (E6MeV, E9MeV, E12MeV, E16MeV and E20MeV) of Varian’s TrueBeam STx and Clinac iX machines. A comparison, between measurement PDDs and calculated by the Eclipse electron Monte Carlo (eMC) algorithm were performed to validate Truebeam Stx commissioning. All this measurements were performed with a Roos and Markus plane parallel chamber. Our measured data indicated that electron beam PDDs from the TrueBeam Stx machine are well matched to those from our Varian Clinac iX machine. Significant differences between TrueBeam and Clinac iX were found in in‐air profiles and open field output. Maximum depth dose for the TrueBeam Stx and Clinac iX for the following energies (6, 9, 12, 16, 20 MeV) are respectively (1.15; 1.89; 2.6; 3.1; and 2.35) and (1.24; 1.95; 2.70; 2.99 and 2.4cm). For the TrueBeam Stx and Clinac iX the quality index R50 for applicator 15x15 cm2 are in the tolerance intervals. Surface dose increases by increasing energy for both machines. The Absolute Dose (cGy/MU) calibrated for both machine in Dmax at 1cGy/MU for the reference field size cone 15x15 cm2. Bremsstrahlung tail Rp per energy levels as follows for the TrueBeam Stx : 6 MeV – 2.85 cm, 9 MeV – 4.28 cm, 12 MeV – 5.97 cm, 16 MeV – 7.88 cm and 20 MeV – 9.86 cm. and for the Clinac iX : 6 MeV – 2.86 cm, 9 MeV – 4.32 cm, 12 MeV – 5.96 cm, 16 MeV – 7.93 cm and 20 MeV – 10.08 cm. A good agreement between modeled and measured data is observed.

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